Related papers: A new algorithm for detecting X-ray shots in Cyg X…
We analyze simultaneous radio-X-ray data of Cygnus X-1 from the Ryle telescope (RT) and RXTE over more than 4 a. We show that apparent correlations on short time scales in the lightcurves of Cyg X-1 are probably the coincidental outcome of…
Cygnus X-1 is a high-mass x-ray binary with a black hole compact object. It is normally extremely bright in hard x-rays and low energy gamma rays and resides in the canonical hard spectral state. Recently, however, Cyg X-1 made a transition…
Time series data mining is an important field of research in the era of "Big Data". Next generation astronomical surveys will generate data at unprecedented rates, creating the need for automated methods of data analysis. We propose a…
Change-point detection regains much attention recently for analyzing array or sequencing data for copy number variation (CNV) detection. In such applications, the true signals are typically very short and buried in the long data sequence,…
Recent monitoring of Cyg X-1 with {\em RXTE} revealed a period of intense flaring, which started in October of 2000 and lasted until March of 2001. The source exhibited some quite unusual behaviors during this period. The soft X-ray flux of…
X-ray sources are developing rapidly and their coherent output is growing extremely rapidly. The increased coherent flux from modern X-ray sources is being matched with an associated rapid development in experimental methods. This article…
We report on the spectral properties of a sample of 90 hard X-ray selected serendipitous sources detected in 12 XMM observations with 1<F(2-10)<80 10^(-14) erg/cm2/s. Approximately 40% of the sources are optically identified with 0.1<z<2…
GX 3+1 is a low-mass X-ray binary that is persistently bright since its discovery in 1964. It was found to be an X-ray burster twenty years ago proving that the compact object in this system is a neutron star. The burst rate is so low that…
The Neupert effect refers to the strong correlation between the soft X-ray (SXR) light curve and the time-integrated hard X-rays (HXR) or microwave flux, which is frequently observed in solar flares. In this article, we therefore utilized…
We present an algorithm to identify individual neural spikes observed on high-density multi-electrode arrays (MEAs). Our method can distinguish large numbers of distinct neural units, even when spikes overlap, and accounts for intrinsic…
We discuss the results of the monitoring programs of the X-ray binaries with relativistic jets studies. We carried out a multi-frequency (1-30 GHz) daily monitoring of the radio flux variability of the microquasars SS433, GRS1915+105, V4641…
The orbital dynamics of Cyg X-3 are a key to understanding this enigmatic X-ray binary. Recent observations by the RXTE ASM and the OSSE instrument on GRO enable us to extend the baseline of arrival time measurements and test earlier models…
An efficient algorithm is presented for the identification of short bursts of gravitational radiation in the data from broad-band interferometric detectors. The algorithm consists of three steps: pixels of the time-frequency representation…
The recent serendipitous discovery of a new population of short duration X-ray transients, thought to be associated with collisions of compact objects or stellar explosions in distant galaxies, has motivated efforts to build up statistical…
Orbital variability has been found in the X-ray hardness of the black hole candidate Cygnus X-1 during the soft/high X-ray state using light curves provided by the Rossi X-ray Timing Explorer's All Sky Monitor. We are able to set broad…
When performing X-ray observations with a Wolter-I telescope, the presence of bright off-axis sources can introduce unfocused rays, known as straylight, which contaminate the detector and compromise the scientific analysis. Among the…
Data selection and the determination of systematic uncertainties in the spectroscopic measurements of neutron star radii from thermonuclear X-ray bursts have been the subject of numerous recent studies. In one approach, the uncertainties…
We introduce new methods for robust high-precision photometry from well-sampled images of a non-crowded field with a strongly varying point-spread function. For this work, we used archival imaging data of the open cluster M37 taken by MMT…
The detection of inelastically scattered soft X-rays with high energy resolution usually requires large grating spectrometers. Recently, photoelectron spectrometry for analysis of X-rays (PAX) has been rediscovered for modern spectroscopy…
In Charge Coupled Device (CCD) detectors the electrons excited upon absorption of a single x-ray photon quickly diffuse and generate charge-spots often larger than pixel dimensions. In the soft x-ray range this phenomenon drastically limits…